This invention relates to a process for the copolymerization of unsaturated polyester resins.
It is well known that the copolymerization of an unsaturated polyester and a reaction monomer may be initiated by many peroxidic initiators.
U.S. Pat. No. 2,740,765 describes the copolymerization of unsaturated polyester resins with the use of an organic peroxide, such as dibenzoyl peroxide, tertiary butyl hydroperoxide, cyclohexyl hydroperoxide, diacetyl peroxide, dilauroyl peroxide or cumene hydroperoxide, in the presence of a quaternary ammonium salt which is soluble in the resin and derived from a non-oxidizing acid which is at least as strong as acetic acid.
Also, U.S. Pat. No. 3,159,690 describes the peroxidic copolymerization of unsaturated polyester resins in the presence of an organic hydroperoxide and an amine salt derived from an acid having a strength which is at least equal to that of acetic acid. To the unsaturated polyesters described in the U.S. Pat. Nos. 2,740,765 and 3,159,690 inhibitors are added to prevent premature gelation.